Okay… is it just a single level?
It's a fine prototype for a game, but it just doesn't have enough content. You're done within a minute.
Also, I have a few tips for improvements if you plan to work on this further.
– There are no sounds. Games with sounds (and possibly music) are instantly more enjoyable.
– The dystopian background is quite cluttered and the foreground with the player doesn't stand out as much.
– For some reason, jumping on the platform at the beginning of the level restarts the game even though it looks exactly the same as the ground. The actual ground hovers a bit above the bottom end of the screen (there's a small gap).
– The cave exit has thin white artifacts around it, and it looks like you saved it as *.jpg, and then attempted to fill it with a paint bucket, which resulted in the uneven fill.
– There's an invisible barrier at the top of the screen, which makes it harder to collect the topmost coins (you have to jump precisely underneath it)
All in all, it's a good start, and I hope you'll continue to work on this, but I don't really think it's a fun game to play at this stage yet.